How to override an array of overlaping timeslots - php

Question

So I need to create a sort of day-per-day calendar with available times, in order for a user to be able to book a meeting with one doctor from a cabinet of multiple doctors.
I hope that this explanation is not too weird already..
Btw I use Laravel 5.5
Here's an example:
Default Schedule of the cabinet : 9:00 to 19:00
Doctor 1 says that on monday, he'll be only available from 13:00 to 15:00
Doctor 2 says that on monday, he'll be only available from 10:00 to 14:00
When I query the available timeslots :
$ids = Doctor::all()->pluck('id');
$workingSchedules = WorkingSchedule::whereIn('user_id', $ids)
->orderBy('start_date')
->whereDate('start_date', '=', $this->datetime->format('Y-m-d'))
->get();
I get:
0 => [
"start_date" => "2017-09-18 10:00:00"
"end_date" => "2017-09-18 14:00:00"
]
1 => [
"start_date" => "2017-09-18 13:00:00"
"end_date" => "2017-09-18 15:00:00"
]
And if nothing shows up from the Database then I use the default cabinet hours.
Then I use Carbon diffInMinutes() method to construct an array of 30 minutes timeslots between those date range (that the user can select).
Anyway, for my script to work correcty I need to transform the result I showed you into this:
0 => [
"start_date" => "2017-09-18 10:00:00"
"end_date" => "2017-09-18 15:00:00"
]
As I only have two timeslots in this example it might be simple a solution, but I might also get an array of 10 timeslots that overlapse one another..
Can somebody help me find a elegant solution that will cover all possible case ?
Thanks a lot in advance.

Answer 1

To be easier, I will suppose $workingSchedules is an array of numbers, then we can easily compare elements
$workingSchedules = [
[
'start_date' => 1,
'end_date' => 5,
],
[
'start_date' => 13,
'end_date' => 16,
],
[
'start_date' => 16,
'end_date' => 17,
],
];
$result = [$workingSchedules[0]];
$index = 0;
foreach ($workingSchedules as $row) {
if ($result[$index]['end_date'] >= $row['start_date']) {
$result[$index]['end_date'] = max($result[$index]['end_date'], $row['end_date']);
} else {
$index++;
$result[] = $row;
}
}
var_dump($result);
Above code will print:
[
[
'start_date' => 1,
'end_date' => 5,
],
[
'start_date' => 13,
'end_date' => 17,
],
]
You can custom the code to compare 2 dates instead numbers
If $workingSchedules is empty, we can simply return default schedule

Answer 2

To merge overlapping time-periods, you could use this code:
$result = [];
$i = -1;
foreach ($workingSchedules as $row) {
if ($i < 0 || $row["end_date"] > $result[$i]["end_date"]) {
if ($i >= 0 && $row["start_date"] <= $result[$i]["end_date"]) {
$result[$i]["end_date"] = $row["end_date"];
} else {
$result[++$i] = $row;
}
}
}
$result will then have non-overlapping periods only.

Answer 3

I hope this will help.
$workingSchedules=array(
0=>array(
"start_date" => "2017-09-18 10:00:00",
"end_date" => "2017-09-18 14:00:00"),
1=>array(
"start_date" => "2017-09-18 13:00:00",
"end_date" => "2017-09-18 15:00:00"
)
);
foreach ($workingSchedules as $schedule){
$start=new DateTime($schedule['start_date']);
$end=new DateTime($schedule['end_date']);
while ($start<=$end){
echo $start->format('Y-m-d H:i')."<br/>";
$start=$start->add(new DateInterval('PT'.'30'.'M'));
}
}